Apparatus for stacking bags

ABSTRACT

AN APPARATUS FOR STACKING BAGS ESPECIALLY BAGS FORMED OF SYNTHETIC PLASTICS MATERIAL IN WHICH THERE ARE UPPER AND LOWER GRIPPING AND SEALING JAWS WITH A MOVABLE CUTTER ASSOCIATED WITH THESE JAWS TO CUT OFF A BAG LENGTH FROM A TUBE OR SHEATH OF MATERIAL, THE LOWER JAW HAVING A FLANGE UNDER WHICH IS DISPOSED A BAG SUPPORT WITH THE FLANGE AND BAG SUPPORT BEING RELATIVELY VERTICALLY DISPLACEABLE TO PERMIT GRIPPING AND HOLDING THEREBETWEEN OF THE END OF A BAG OR STACK OF BAGS AND RETAINING MEMBER FOR HOLDING THE BAG ON THE SUPPORT UNTIL THE BAG TAKES UP A FLAT CONDITION.

United States Patent m13,ss7,410

[72] Inventor Bernard Dechanciaux [56] References Cited Eflmmt- Frill UNITED STATES PATENTS 3 gir 3 1969 2,069,592 2/1937 Potdevin 93/33 l 2,705.443 4/1955 Colby ,3 93/33 [32] Priority June 26, [968 Primary Examiner-Travis S. McGehee [33] France Attorney-Steinberg and Blake 7 G L .E t,F c l 31 Asslbnee eorges ogam rmon ran e ABSTRACT: An apparatus for stacking bags especially bags formed of synthetic plastics material in which there are upper and lower gripping and sealing jaws with a movable cutter associated with these jaws to cut off a bag length from a tube or sheath of material, the lower jaw having a flange under which [54] fi i g? STECKING BAGS is disposed a bag support with the flange and bag support rawmg being relatively vertically displaceable to permit gripping and [52] US. Cl 93/33 holding therebetween of the end of a bag or stack of bags and [51] Int. Cl B3lb 1/14 retaining member for holding the bag on the support until the [50] Field of Search 93/33 bag takes up a flat condition.

APPARATUS FOR STACKING BAGS This invention relates to apparatus for stacking bags.

There are known machines for manufacturing bags from a tube or sheath of synthetic plastics material which is conveyed to a location where it is cut and sealed at predetermined intervals.

At the outlet of such machines the bags are stacked flat and substantially horizontally.

According to one known method, the bags are ejected by means of belts and come to rest due to gravity on the bags which are already stacked.

According to other known methods, grippers or belts can be employed which ensure displacement of the bags to the stack of bags on which they are to be located.

These different methods operate efficiently when the bags are relatively thick and are of convenient shapes. However, when the bags are made ofa very thin material such as plastics material, and are of relatively great length, stacking is irregular, due to folding-of the bags caused by the suppleness of the material from which-they are produced and also the relatively great length ofthe bags.

According to the present invention there is provided apparatus for stacking bags and capable of being arranged at the outlet of a machine for manufacturing bags from a tube or sheath ofmaterial, the apparatus comprising upper and lower sealing jaw means, at least one of which is vertically movable, vertically movable severing means associated with the jaw means for cutting a length of material from the tube or sheath to form a bag, flange means extending outwardly from the lower jaw means, support means disposed below the flange means and cooperating with same to grip therebetween one end of a bag or stack of bags, the flange means and support means being relatively vertically displaceable, and vertically movable retaining means for cooperating with the support means to hold the bag or stack of bags on the support means until the or each newly formed bag lies flat on the support means.

The apparatus provides efficient arrangement and obviates or mitigates the disadvantages mentioned above, since the bags are held secure during their displacement by means of the retaining means which engages the tube or sheath before the latter is cut.

Phenomena resulting from static electricity which cause dispersal of the bags when they are piled flat aresuppressed.

On the other hand, due to the flat stacking, it is possible to stack together both very short bags and very long bags, which is not the case when using a rounded or curved stacking locatron.

It is also possibleto stack small bags when using a lateral sealing as opposed to end sealing.

Finally, the apparatus is of small bulk, so that it can easily be disposed at the outlet of any machine for manufacturing the bags.

Embodiments of the present invention will now be described, by way of example with reference to the accompanying drawings, in which:

FIG. I is a side elevation of the apparatus for stacking bags according to the invention, disposed at the outlet ofa machine for manufacturing bags;

FIG. 2 is an identical view to that of FIG. 1, showing the apparatus in an intermediate operating position;

FIG. 3 is an identical view to that of FIG. 1, showing the apparatus at the instant of removal of the support member from the lower sealing jaw for stacking a new bag;

FIG. 4 is a side elevation of another embodiment ofthe apparatus for stacking bags, according to the invention;

FIG. 5 is a plan viewof a two-part table as used in the apparatus of FIG. 4, and

FIG. 6 is an elevation of yet another embodiment of apparatus for stacking bags, according to the present invention.

In FIGS. 1,2 and 3, there is shown the outlet ofa machine for manufacturing bags comprising a table I over which is conveyed the tube or sheath 2 of synthetic plastics material,

the tube 2 being displaced through the machine in the direction of the arrow F, and two sealing jaws, namely an upper jaw 3 and a lower jaw 4 arranged above and below the tube 2 respectively and including respectively an electric resistance 5 and 6 thus ensuring heat sealing of one of the edges of the tube 2 so as to form the bottom ofa bag.

The lower jaw 4 is stationary, while the upper jaw 3 is moved in the direction ofthe arrow F by convenient means to contact the lower jaw 4 during the operation of sealing the tube 2 which at that instant is gripped between the two jaws.

In known manner, the upper sealing jaw 3 has integral therewith a cutting member 7 located forwardly of the sealing electric resistance 5 in the direction of movement of the tube or sheath The lower jaw 4 has a flange 8 extending forwardly of the jaw 4 in the direction of movement of the tube 2 and against which can be urged a member or rule 9 for supporting a stack of bags. The support member 9 is mounted in the frame 11 of the machine so as to slide upwardly and downwardly in the direction of the double arrow F relative to the lower jaw 4, the support member 9 being subject to the action of a spring or springs 10 supported in the frame I].

One end of stacked bags 12 is maintained between the upper surface 9a of the support member 9 and the lower surface of the flange 8 of the lower jaw 4 which bag ends rest on the surface 9a of the support member 9.

In front of the cutting member 7 in the direction of movement of the tube 2 and above the support member 9, there is slidably mounted in convenient guides a retaining member 13 which has on the rear of its lower edges a compressed air pipe 14 pierced by apertures 15 for blowing compressed air on the severed and closed end ofa bag when it is stacked.

Similarly to the upper jaw 3, the retaining member 13 which is bar shaped, is driven by known mechanical means which are not shown in the drawings, in the direction of the arrow F for contacting the bags 12 arranged on the surface of the support member 9.

In front of the support member 9 again in the direction of movement of the tube 2, there is arranged a stationary table 16 having an inclined surface intended to receive the free ends 12a ofthe bags 12.

The stacking apparatus according to the invention operates in the following manner:

In FIG. 1, the apparatus is shown during the stage ofdisplacing a given length of plastics tube or sheath 2, which is to constitute a bag. At this instant the upper jaw 3, the cutting member 7 and the retaining member 13, are in the upper positron.

As soon as the movement of the tube or sheath 2 is arrested, the retaining member 13 is lowered in the direction of the arrow F to hold the tube or sheath 2 in position on the stack of bags 12 resting on the surface 90 of the support member 9, as is illustrated in FIG. 2.

Then, the upper jaw 3 is lowered in the direction of arrow F,, for carrying out in turn, the cutting and the sealing of the severed end of the tube or sheath.

As soon as the severing of the tube or sheath has been effected, the retaining member 13, which was momentarily arrested in the position of FIG. 2, continues to move downward in the direction of the arrow F pushing the support member 9 downwardly against the action of the springs 10, in order to cause movement of the support member 9 away from the flange 8 ofthe lowerjaw 4.

As shown in FIG. 3, it is thus possible for the end 17a of the top bag 17, which has just been severed to fall flat on to the stack of bags 12.

In order to facilitate this operation there is directed a jet of compressed air through the apertures 15 in the pipe 14 onto the end 17a ofthe top bag 17.

When the top bag 17 is arranged flat on the stack of bags 12, the retaining member 13 reascends in the direction opposite to that of the arrow F in order to occupy its initial position as shown in FIG. 1.

Under the action of the springs 10, the support member 9 again moves upwards towards the flange 8 of the lower jaw 4 in order to sandwich one end of the stack of bags including the top bag 17 between the flange 8 and support member 9.

The stacking apparatus, which is again in the position of FIG. I, is ready to receive the next bag.

In a modification, it is possible to use a support member 9 which is stationary relative to the frame 11 of the machine and a lower sealing jaw 4 which is vertically movable in such a way that after the cutting and sealing operations, the jaw 4 is entrained in an ascending movement in order to allow the engagement of the end 170 of the top bag 17 between the flange 8 and the support member 9.

This modification would necessitate an additional mechanical movement for movingthe lowerjaw 4.

In FIGS. 4 and there is shown another apparatus for stacking bags and comprising, as above, two sealing jaws, namely an upper jaw- 3 and a lower jaw 4 arranged above and below a tube or sheath 2'and including respectively an electric resistance 5 and 6 to ensure heat sealing of one of the edges of the tube or sheath 2 so as to form the bottom of the bag.

Below the surface 8a of'the flange 8 of the lower jaw 4 there is disposed one of the end of a table 18 on which there are stacked the bags which are kept gripped between the flange 8 and the table 18, which is pivotally mounted at its other end about a pivot 19 integral with the frame of the machine.

The table 18 is urged towards the flange 8 under the action of a spring lever 20 fixed to the frame at 21 and acting at its end 22 on the table 18, in the direction of the arrow A.

As described above, a retaining member 13, arranged in advance of the cutting member 7 acts on the table 18 against the action of the spring 20 to push the table 18 downwards and permit insertion of a new bag 12 between the flange 8 and the table 18.

The table 18 is constituted by two parts 18a, 18b (FIG. 5) which are pivotally mounted on the pivot 19 and which are subject respectively to the action of springs 20a, 20b. This arrangement makes it possible to operate the machine with two or more tubes or sheaths.

According to the embodiment of the apparatus shown in FIG. 6, there is employed a table 23 manufactured from a material which is itself resilient which makes it possible to omit the spring or springs 20.

In this case, the table 23 is fixed at one of its ends to a support bar 24 integral with the machine frame and as in the embodiment of FIG. 4 it is urged at its other end against the projecting flange 8 of the lowerjaw 4.

This table 23 may be constituted by a steel sheet.

Iclaim:

I. Apparatus for stacking bags and capable of being arranged at the outlet ofa machine for manufacturing bags from a tube or sheath of material, the apparatus comprising upper and lower sealing jaw means, at least one of which is vertically movable, vertically movable severing means associated with the jaw means for cutting a length of material from the tube or sheath to form a bag, flange means extending outwardly from the lower jaw means, support means disposed below the flange means and cooperating with same to grip therebetween one end of a bag or stack of bags, the flange means and support means being relatively vertically displaceable, and vertically movable retaining means for cooperating with the support means to hold the bag or stack of bags on the support means until the or each newly formed bag lies flat on the support means.

2. Apparatus according to claim 1, in which the support means is slidable parallel to the lower jaw means, resilient means being provided to urge the support means towards the flange means of the lower jaw means to effect gripping of the bag or stack of bags.

3. Apparatus according to claim 2, in which the support means and ledge means are the same width.

4. Apparatus according to claim I, in which the retaining means extends over the entire width of the upper sealing jaw, means being provided to mount the retaining means so as to permit same to slide parallel to the upper sealing jaw means.

5. Apparatus according to claim 1, in which the support means is stationary, and the lower sealing jaw means is mounted to slide parallel to the support means.

6. Apparatus according to claim 1, comprising air blowing means mounted on one of the lower edges of the retaining means and directed towards the sealing jaw means.

7. Apparatus according to claim 1, comprising a stationary table having an inclined surface on which the stacked bags rest and disposed adjacent the support means.

8. Apparatus according to claim 1, comprising a pivotable support table on which the bags can be stacked, and spring means for urging one end of the support table towards the flange means of the lower sealing jaw means to grip the bags.

9. Apparatus according to claim 8, in which the said table is mounted on a frame at its nongripping end for movement about a pivot extending parallel to the jaw means.

10. Apparatus according to claim 8, in which the support table comprises at least two parts pivotally mounted about a common pivot extending parallel to the jaw means.

ll. Apparatus according to claim 8, in which the support table is made from a material having an inherent resilience certain elasticity and abuts at one ofits ends against the flange means while it is fixed at its other end to a stationary support. 

